Dora Bas Rivka Silver O'H
G-d instructed Moshe in how to take a census of the Jews. A simple head count wouldn't do, as that would lead to a plague (as we see actually happened in II Samuel chapter 26). Instead, they should be counted by collecting a half-shekel coin from each of them, then counting the coins. The census was to count males over the age of 20 and the denomination of a half-shekel was non-negotiable. Not only were people not allowed to give less, they weren't allowed to give more. The money collected was to be used for building the Mishkan.
Another vessel of the Mishkan was to be the Kiyor, a large copper wash basin from which the kohanim would wash their hands and feet. Failure to do so would be a serious offense.
G-d also gave Moshe the formula to make the precious scented oil, with which the High Priest would be anointed. The Mishkan and all of the vessels would likewise be anointed in order to be sanctified. This formula of oil, which is described in verses 23-24, was only to be used for this purpose; it is strictly forbidden to make or use this formula for anything else.
Another thing G-d told Moshe was the "recipe" for the incense, which was likewise prohibited to replicate.
G-d told Moshe that He had selected Betzalel the grandson of Chur as the chief architect of the Mishkan. (Chur was Miriam's son.) G-d gave Betzalel the talent for the job. He also appointed Oholiav of the Tribe of Dan to assist Betzalel, along with other skilled craftsmen. (The Tribe of Dan was apparently renowned for such things; Hiram, the architect of the Temple, was descended from Dan on his mother’s side – see II Chronicles 2:13.) Together, they would make the Mishkan, its vessels and all the priestly garments.
At this point, the Torah interrupts the instructions for building the Mishkan to remind us about Shabbos. Even though building the Mishkan is a holy endeavor, they must knock it off each week in order to keep Shabbos. (From here it is derived that the Sabbath categories of labor are the activities necessary in building the Mishkan.)